Can Registered power agent allowed by Court (40 Yrs Son of Plaintiff ) can depose for Principle in a partition suit ?

Situation : Respected Team, I very humbly request you to please give me answer as well as recent Citations of Supreme Court of India and Madras High Court on the related Issues..We all will be Life time thankful to you and your organization. In a Civil OS ( Partition Suit ) Matter : My Mother have Given me an Registered Power of Attorney Which was allowed by Principle Court. Power of Attorney holder has given evidence and the process of cross examination is also done . Question Are : 1, Whether Registered power agent allowed by Court ( 40 yrs Son of Plaintiff ) can depose for Principle in a partition suit ? 2, Whether Principles of res judicata applies for suit for partition in view of previous suit dismissed for default by both ( Plaint and Respondent ) ? 3, Whether unprobated will ( Un registered )of christian let in evidence after 2002 amendment in indian succession act ? 4, Whether will ( unregistered ) without examining of one of the attesting witness can be proved ? 5, Whether Sale of property without probate before 2002 amendment in indian succession act is valid ? ( 1992 Registration ) ( Christian ) 6, What are the Suspicious Circumstances in Executing of WILL ? 7, How to Prove a Unreg